The best way to work as a skilled individual in Nigeria is to sign up as a freelancer on a freelance platform or website.
What these websites or platforms do is that they serve as an escrow between you and your buyer or seller.

What an escrow does is protect the interest of both parties.

[For instance on ][https://timijobs.com] what they do is a buyer pays into their company's account and the money remains there until the seller delivers his job before he is paid.

This way there will be nothing like the seller blocked my line after the money was paid

Or the buyer refuses to pay the money after the job was delivered.

One of the Freelance platforms in Nigeria is Timi Jobs

This video shows you how to sign up on Timi Jobs and earn income working for anyone from any part of Nigeria.
Watch the video here

https://www.youtube.com/watch?v=h5thby9tIRs